Final Project Overview

Problem Statement

Among those who take cholesterol lowering medication, does taking this medication have an effect on their systolic blood pressure?

Background

Controlling blood pressure reduces the risk for cardiovascular disease.
Systolic above 130 mmHg is considered to be hypertensive.
Doctors often prescribe both antihypertensive and cholesterol-lowering drugs, as patients with high blood pressure often have high cholesterol.
Ways to control blood pressure include exercise, pharmacotherapy, a healthy diet, regulating sodium, reducing alcohol use, smoking, getting sleep, reducing stress, and regular health check-ups.

DAG

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Statistical Analysis

Clean the dataset
Build a propensity model and ATT weights
Run diagnostics on the propensity model
Build an outcome model
Run sensitivity analysis

Key Results

The cleaned data had 20,822 rows and 8 columns after deriving \(X, Y, \boldsymbol{Z}\) from our adjustment set and dropping missing values.
The propensity model and ATT weighting produced data that was balanced.
Using a sandwich estimator to derive the standard errors, we observe an ATT of -3.746 with 95% CI (-4.782,-2.71).
A conservative unmeasured confounding variable setup would require an effect size of over 6 times the ATT to tip the CI to the null at the 95% level.

Diagnostic Plots

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Diagnostic Plots

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Diagnostic Plots

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Conclusion

Given our observed ATT of -3.746 with 95% CI (-4.782,-2.71), we conclude that those currently taking medication should continue to take this medication, as it lowers their systolic blood pressure.